[time-nuts] Averaging Location for Position Hold

Miguel Gonçalves mail at miguelgoncalves.com
Wed Sep 14 08:06:27 UTC 2011


On 14 September 2011 05:36, Mark Sims <holrum at hotmail.com> wrote:

> Lady Heather's precision (nominal 48 hour) survey collects data over
> multiple 1 hour periods.  With 48 hours of data,  multipath and transient
> disturbances are minimized.  It applies weighted median filters  to the data
> and does other statistical analysis to arrive at a final location.  With a
> good choke-ring antenna you can get within under a foot.  With a crappy
> patch antenna without a ground plane maybe 6 feet.   Simple averaging of the
> survey samples does not perform nearly as well.

Will do. Thanks!

> As far as Lady Heather not working with other GPSDO's...  well,  She has
> good taste.  The Trimble Thunderbolt is far and away the best time-nut GPSDO
> out there.  It is highly configurable and controllable,  comes with a very
> good OCXO,  and is dirt stinkin' cheap.  If you dot all your i's and cross
> all your t's and pay very close attention to the details you can coax
> ridiculously high performance out of the tiny little box...  rivaling the
> best cesium references made for under $200.

This is why I am looking at some units on eBay. :-)

One, perhaps, silly question: when it looses lock it continues to issue the
PPS (hold-over mode) but does the second numbering continues also through
RS-232? This is going to be used for an NTP server.


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